Alert archive / Maryland / Flash Flood Warnings in 2001

Flash Flood Warning 32, NWS Baltimore/Washington

June 22, 2001Howard County, Maryland

NWS Baltimore/Washington issued this flash flood warning at Jun 22, 2001, 10:41 PM EDT for Howard County, Maryland. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jun 22, 2001, 10:41 PM EDT (02:41 UTC)
Expired: Jun 23, 2001, 1:45 AM EDT
In force: 3 hr
Issued by: NWS Baltimore/Washington
Area: Whole counties

County Howard County, MD

The radar

The Sterling radar (KLWX), 57 km from the middle of the area, began a volume at 02:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 2.7 hours before the alert went out and 198 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 483 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 854 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: -11 m²/s²
0-3 km storm-relative helicity: 26 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS51 KLWX 230241
FFWLWX
MDC027-230545-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BALTIMORE-WASHINGTON
1041 PM EDT FRI JUN 22 2001

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  HOWARD COUNTY IN CENTRAL MARYLAND

* UNTIL 145 AM EDT

* AT 1038 PM EDT...WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAINFALL 7 MILES WEST OF COLUMBIA...
  MOVING NORTHEAST AT 15 MPH.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE 
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. QUICKLY 
MOVE OUT OF AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

IF WATER IS FLOWING ACROSS A ROADWAY TURN YOUR VEHICLE AROUND AND
FIND AN ALTERNATE ROUTE. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW
YOUR CAR TO CROSS SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED QUICKLY. MOVE TO HIGHER GROUND.

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Baltimore/Washington wrote its last area forecast discussion before this flash flood warning went out at Jun 22, 8:20 PM EDT, 2 hours 21 minutes earlier.

Area forecast discussion, Jun 22, 8:20 PM EDT, 2 hours 21 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
820 PM EDT FRI JUN 22 2001

UPDATED ZONES AT 7PM TO DROP EXPIRED SVR TSTM WATCH AND ADD MENTION
OF SVR TSTM WATCH ISSUED FOR MOST OF E CWA IN EFFECT UNTIL 11 PM.
FLASH FLOOD WATCH REMAINS IN EFFECT FROM BLUE RIDGE WEST AND CHO
AREA UNTIL 4 AM SAT MORNING.

REGIONAL RADAR SHOWS NUMEROUS SHOWERS AND TSTMS OVER S VA AND N NC
MOVING NNE AHEAD OF COLD FRONT. MODELS SHOW DYNAMIC SUPPORT FOR
PRECIP OVER CWA THROUGH AT LEAST 06Z. EXPECT RAIN TO CONTINUE
THROUGH EARLY MORNING HOURS AND FOR FLASH FLOODING TO REMAIN A
PROBLEM. EXPECT WIND/HAIL THREAT TO DIMINISH BEFORE MIDNIGHT DUE TO
LOSS OF DIURNAL HEATING THAT DROVE STORMS IN HIGH CAPE ENVIRONMENT.
WILL UPDATE ZONES AGAIN AT 11 PM WHEN WATCH EXPIRES.

.LWX...
DC...NONE.
MD...FLASH FLOOD WATCH THRU 400 AM FOR ZONES MDZ002>003.

VA...FLASH FLOOD WATCH THRU 400 AM FOR ZONES VAZ021...VAZ025>v031...
VAZ036>040...VAZ050>051.

WV...FLASH FLOOD WATCH THRU 400 AM FOR ZONES WVZ048>055.

MMARGRAF

In the hours before

Local storm report, Jun 22, 6:24 PM EDT, 4 hours 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
624 PM EDT FRI JUN 22 2001

TIME(EDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0450 PM    NORTHWEST PORTION         VA   FLASH FLOODS
06/22/01   WARREN                         ROADS FLOODED. REPORTED BY
                                          LAW ENFORCEMENT.

0530 PM    SHAWNEELAND               VA   FLASH FLOODS
06/22/01   FREDERICK                      ACCESS ROAD TO SHAWNEELAND
                                          DEVELOPMENT WASHED OUT.
                                          TRAFFIC NOT ABLE TO LEAVE
                                          OR ENTER DEVELOPMENT.
                                          REPORTED BY EMERGENCY
                                          MANAGEMENT.

0545 PM    COUNTYWIDE                VA   FLASH FLOODS
06/22/01   NELSON                         WATER COVERED ROAD NEAR
                                          NELSON COUNTY HIGH SCHOOL.
                                          REPORTED BY 911 CENTER.

0555 PM    COUNTYWIDE                VA   FLASH FLOODS
06/22/01   LOUDOUN                        FLOODING REPORTED BY 911
                                          CENTER. 3.25 INCHES OF
                                          RAINFALL REPORTED IN
                                          LEESBURG.

0605 PM    ASHBURN                   VA   60 MPH TSTM WIND GUST
06/22/01   LOUDOUN                        ESTIMATED 60 MPH WIND GUST
                                          BY SPOTTER.

MKM

Local storm report, Jun 22, 8:12 PM EDT, 2 hours 29 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
812 PM EDT FRI JUN 22 2001

TIME(EDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0615 PM    LEESBURG                  VA   .88 INCH HAIL
06/22/01   LOUDOUN                        DIME SIZED HAIL REPORTED
                                          BY SPOTTER.

0630 PM    4 W ASHBURN               VA   WIND DAMAGE
06/22/01   LOUDOUN                        POWERLINES DOWN ON BELMONT
                                          RIDGE ROAD NEAR THE
                                          GREENWAY. REPORTED BY
                                          SKYWARN.

0645 PM    COUNTYWIDE                VA   FLASH FLOODS
06/22/01   LOUDOUN                        WATER OVER INTERSECTION OF
                                          ROUTE 7 AND ASHBURN
                                          VILLIAGE ROAD. 2 FEET OF
                                          WATER IN INTERSECTION OF
                                          ROUTE 7 AND 659. REPORTED
                                          BY SPOTTERS.

0710 PM    SOUTHWEST PORTION         MD   FLASH FLOODS
06/22/01   ALLEGANY                       FLOODING IN RAWLINGS. ONE
                                          TREE DOWNED ONTO A
                                          POWERLINE IN FROSTBURG.
                                          REPORTED BY EOC.

0730 PM    HANGING ROCK              VA   FLASH FLOODS
06/22/01   SHENANDOAH                     RIVERS RISING RAPIDLY NEAR
                                          HANGING ROCK AND ROUTE 259
                                          AND 612. HELICOPTER RESCUE
                                          OF WOMAN IN CAR. REPORTED
                                          BY SKYWARN.

0745 PM    FULKS RUN                 VA   FLASH FLOODS
06/22/01   ROCKINGHAM                     EVACUATING AREA BETWEEN
                                          BERGTON AND BROADWAY DUE TO
                                          FLOODING. REPORTED BY 911
                                          CENTER.

MKM

The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 22, 8:41 PM EDT	Flash Flood Warning	LWX	Howard	3 hr
Jun 22, 9:55 PM EDT	Flash Flood Warning	LWX	Carroll	3 hr
Jun 22, 10:30 PM EDT	Flash Flood Warning	LWX	Montgomery	3 hr
Jun 23, 1:03 AM EDT	Flash Flood Warning	LWX	Carroll	57 min

Nearby

Flash Flood Warnings in Maryland, 2001 Every flash flood warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.